use native promise constructor

README.md

@@ -3,7 +3,7 @@
  * @Author: ekibun
  * @Date: 2020-08-08 08:16:50
  * @LastEditors: ekibun
- * @LastEditTime: 2020-08-27 21:11:55
+ * @LastEditTime: 2020-09-22 00:03:48
 -->
 # flutter_qjs
 
@@ -11,13 +11,13 @@ A quickjs engine for flutter.
 
 ## Feature
 
-This plugin is a simple js engine for flutter using the `quickjs` project. Plugin currently supports Windows, Linux, and Android.
+This plugin is a simple js engine for flutter using the `quickjs` project with `dart:ffi`. Plugin currently supports Windows, Linux, and Android.
 
-Each `FlutterJs` object creates a new thread that runs a simple js loop. 
+Event loop of `FlutterQjs` should be implemented by calling `FlutterQjs.dispatch()`. 
 
 ES6 module with `import` function is supported and can manage in dart with `setModuleHandler`.
 
-A global async function `dart` is presented to invoke dart function, and `Promise` is supported so that you can use `await` or `then` to get external result from `dart`. Data convertion between dart and js are implemented as follow:
+A global function `convert` is presented to invoke dart function. Data convertion between dart and js are implemented as follow:
 
 | dart | js |
 | --- | --- |
@@ -25,54 +25,50 @@ A global async function `dart` is presented to invoke dart function, and `Promis
 | Int | number |
 | Double | number |
 | String | string |
-| Uint8List/Int32List/Int64List | ArrayBuffer |
-| Float64List | number[] |
+| Uint8List | ArrayBuffer |
 | List | Array |
 | Map | Object |
-| Closure(List) => Future | function(....args) |
+| JSFunction | function(....args) |
+| Future | Promise |
 
-**notice:**
-1. All the `Uint8List/Int32List/Int64List` sent from dart will be converted to `ArrayBuffer` without marked the size of elements, and the `ArrayBuffer` will be converted to `Uint8List`.
-
-2. `function` can only sent from js to dart and all the arguments will be packed in a dart `List` object.
+**notice:** `function` can only sent from js to dart.
 
 ## Getting Started
 
-1. Create a `FlutterJs` object. Make sure call `destroy` to terminate thread and release memory when you don't need it.
+1. Create a `FlutterQjs` object. Call `dispatch` to dispatch event loop.
 
 ```dart
-FlutterJs engine = FlutterJs();
-// do something ...
-await engine.destroy();
-engine = null;
+final engine = FlutterQjs();
+await engine.dispatch();
 ```
 
 2. Call `setMethodHandler` to implements `dart` interaction. For example, you can use `Dio` to implements http in js:
 
 ```dart
-await engine.setMethodHandler((String method, List arg) async {
+await engine.setMethodHandler((String method, List arg) {
   switch (method) {
     case "http":
-      Response response = await Dio().get(arg[0]);
-      return response.data;
+      return Dio().get(arg[0]).then((response) => response.data);
     default:
-      return JsMethodHandlerNotImplement();
+      throw Exception("No such method");
   }
 });
 ```
 
-and in javascript, call `dart` function to get data:
+and in javascript, call `convert` function to get data, make sure the second memeber is a list:
 
 ```javascript
-dart("http", "http://example.com/");
+convert("http", ["http://example.com/"]);
 ```
 
-3. Call `setModuleHandler` to resolve js module. For example, you can use assets files as module:
+3. Call `setModuleHandler` to resolve js module.
+
+**important:** I cannot find a way to convert the sync ffi callback into an async function. So the assets files got by async function `rootBundle.loadString` cannot be used in this version. I will be appreciated that you can provied me a solution to make `ModuleHandler` async.
 
 ```dart
-await engine.setModuleHandler((String module) async {
-  return await rootBundle.loadString(
-      "js/" + module.replaceFirst(new RegExp(r".js$"), "") + ".js");
+await engine.setModuleHandler((String module) {
+  if(module == "hello") return "export default (name) => `hello \${name}!`;";
+  throw Exception("Module Not found");
 });
 ```
 
@@ -82,7 +78,7 @@ and in javascript, call `import` function to get module:
 import("hello").then(({default: greet}) => greet("world"));
 ```
 
-4. Use `evaluate` to run js script, and try-catch is needed to capture js exception.
+4. Use `evaluate` to run js script:
 
 ```dart
 try {
@@ -92,4 +88,6 @@ try {
 }
 ```
 
+5. Method `recreate` can free quickjs runtime that can be recreated again when calling `evaluate`, it can be used to reset the module cache. Call `close` to stop `dispatch` when you do not need it.
+
 [This example](example/lib/main.dart) contains a complete demonstration on how to use this plugin.